The invention relates to an electric motor having a stator and a rotor, the stator and/or rotor having winding carriers of a winding having at least two terminals, the winding carriers being connected individually to the stator and/or rotor in a detachable manner.
Electric motors or generators are one of the most important electrical machines. They are used in the most diverse forms and in many different areas of everyday life. An essential feature of the electric motor is that it converts electrical energy into mechanical work. In this case, it is usually constructed as a rotating machine, a rotor rotating about a stator. The rotor may be the actual armature, or else, in particular in wheel-hub motors, the rotor may be the outer exciter part, which surrounds the armature part and is then connected, for example, to a rim or the like.
The manufacture of commercially available motors involves some difficulties. The exciter part and/or the armature part have carriers, slots or the like around which or in which windings are placed. In most cases, this is done by hand.
In WO96/23344, for example, a manufacturing process for a motor is shown in which it is already possible to wind the winding carriers automatically. To this end, the winding carriers are wound before they are connected to the stator and/or rotor. They are then inserted into axially parallel slots and are secured there.
DE 36 38 228 A1 describes an electric motor (external-rotor salient-pole motor) with a stator and a rotor, the stator having winding carriers with in each case a winding having at least two terminals. These adjacent winding carriers are each connected separately to the stator.
GB-A 2 310 545 discloses an electric motor in which adjacent winding carriers are connected to one another at their outer circumference.
Furthermore, there are difficulties in securing the winding carriers to the stator and/or rotor and in particular also with the electrical connection of the individual windings, the winding carrier being oriented as north or south pole by this electrical connection.
DE 829 613 C discloses an electric motor of the aforesaid type. This electric motor is designed in such a way that two adjacent winding carriers are inserted into a dovetail slot of a yoke body and are restrained there by wedge-like parts.
The object of the present invention is to further simplify the manufacture of an electric motor to a considerable extent and reduce power losses in the process.
The foregoing object is achieved in that a plate, a ring or the like which encloses an angle of less than 90xc2x0 with the stator and/or rotor projects from the stator and/or rotor, a fastening element pressing the winding carriers with their root region into this angle.
The configuration of the winding carriers has the advantage that the motor is manufactured virtually according to the modular construction principle. It can easily be assembled and easily be dismantled again. The winding carriers are wound before the assembly, so that there is nothing to prevent automatic winding.
A root region of the winding carrier is in particular suitable for connecting the winding carriers to one another or for connecting the winding carriers by means of a common fastening element. For example, if a stator is located as armature core in the center of the motor, the winding carriers can be arranged to protrude radially from this armature core. In this case, their root regions preferably abut against one another and are either connected to one another or are secured via a common fastening element.
If, for example, screw bolts are used as fastening elements and these are tightened, the winding carriers or their root regions are pressed into the angle between armature core and plate, so that the winding carrier bears effectively against the armature core.
The screw bolt engages in a tapped hole in a plate which is assigned to the armature core. This plate forms a projecting ring, so that the winding carriers sit on this plate.
For the sake of simplicity, the connection by means of a common fastening element is effected by slots being formed laterally in the root region of the winding carrier, in which case two slots of adjacent winding carriers together form a locating bore for a screw bolt for example. For this reason, the side flanks of the root region are preferably designed so as to run conically to one another, in which case they preferably run radially in the direction of a center of the armature core.
Furthermore, the slots also have the advantage during winding that clamping claws which hold the winding carrier in place during the winding can engage in these slots. As a result, the winding is also substantially facilitated.
In another exemplary embodiment of the invention, a positive-locking connection between the winding carriers is also intended. This may be done, for example, by a slot/key connection of dovetail design.
To secure the winding carriers to the armature core, plates which overlap the root region of the winding carriers may be screwed on, for example, on both sides.
It is also conceivable for each individual winding carrier to be connected separately to the rotor and/or stator. In one exemplary embodiment, a fastening element, for example a screw, which passes through the root region of the winding carrier, is sufficient for this purpose.
However, the present invention directs particular attention toward the securing of the lugs of the winding. The intention is for the windings to be always wound onto the winding carrier in the same direction, so that no importance has to be attached to a subsequent north or south orientation during the winding of the winding carrier. The orientation of the winding carrier is selected after the winding carriers have been put onto the stator or rotor, a printed board which has two separate strip conductors being assigned to the winding carriers. One strip conductor is connected to a positive pole, and the other strip conductor is connected to a negative pole. The two terminal lugs project from each winding carrier, the one or the other lug being connected to the one or the other pole depending on the desired orientation of the winding carrier. This is done in a simple manner by virtue of the fact that the lug is pushed through the printed board and soldered to the appropriate strip conductor. This may be done in a common solder bath after the lugs of all the winding carriers have been pushed through.
In addition, further components for control of the motor may be arranged on the printed board. In the case of powerful motors, the printed boards may also be stacked or have a multilayer construction. Many possibilities which are to be covered by the present invention are likewise conceivable here.
The winding carriers preferably consist of individual stacked laminations. According to the invention, precision machining of these winding carriers is to take place after the stacking, the side faces in particular being machined. This results in a further mechanical connection of the individual laminations, which leads to an improvement in the magnetic property. Furthermore, the magnetic property of the winding carrier may also be favorably influenced by the selection of the thickness of the laminations.